The formation of the modern Imperial Japanese Navy dates from 1868 with the Meiji Restoration, and its first fleet, the Northern Expeditionary Fleet, was assembled in 1869 for the final naval campaign of the Boshin War against Tokugawa separatists who had fled to Hokkaido. The first Combined Fleet sailed in support of operations against China during the First Sino-Japanese War (1894-1895). A second Combined Fleet was assembled during the Russo-Japanese War (1904-1905). After the start of hostilities in Manchuria a permanent HQ staff for the Combined Fleet was established in 1932, coming under the direct command of the Imperial General Headquarters in 1937 with the onset of the Second Sino-Japanese War (1937-1945), continuing through the Pacific War (1941-1945) until Japan’s surrender in 1945.
In 1936, the main bodies of the Imperial Japanese Navy were comprised of the 1st Fleet, the 2nd Fleet, and the 3rd Fleet. The 1st and 2nd Fleets were designed as mobile strike forces, each composed of an assortment of battleships or heavy cruisers, battlecruisers and/or armored cruisers, light cruisers, destroyers, submarines, and aircraft carriers. The 3rd Fleet was also known as the “China Area Fleet”, as its assignments were primarily in support of operations along the Chinese coast and interior waterways with an assortment of armored cruisers, destroyers, river gunboats and seaplane tenders.
First Fleet (1936)
Commander: Admiral Takahashi Sankichi (also C-in-C of the Combined Fleet)
Composed of: 1st Squadron (including the battleships Nagato, Haruna), 3rd Squadron (including the battlecruisers Kirishima, Haruna), 8th Squadron (including the light cruisers Jintsu, Nagara, Sendai), 1st Destroyer Squadron, 1st Submarine Squadron, 1st Air Fleet (including the aircraft carrier Ryujyo).
Takahashi, an important figure of the IJN’s “Fleet Faction”, had a swift career rise, from commander of an obsolete cruiser in 1923 to commander of the Combined Fleet in 1934. He was instrumental in crushing the opposing moderate “Treaty Faction” (those who supported the 1922 treaty and the 1930 London Naval Treaty, and avoid war with the United States). Takahashi later recalled that “one of his aims [in the 1932 struggle for power] was to be prepared with a war with the United States.” In November 1934, Takahashi was appointed Commander of the Combined Fleet and held the command for two years while also in command of the First Fleet. Contrary to the battleship mentality of the old-school admirals, he spoke in favor of increasing aircraft carrier arm of the Fleet; his opinion was rejected by both General Staff and the Navy Ministry and ultimately cost him his career.
Second Fleet (1936)
Commander: Vice-Admiral Kato Takahoshi
Composed of: 5th Squadron (including the heavy cruisers Myoko, Haguro, Nachi), 7th Squadron (including the heavy cruisers Kinugasa, Aoba), 2nd Destroyer Squadron, 2nd Submarine Squadron, 2nd Air Fleet (including the aircraft carrier Kaga).
Kato was promoted to Commander of the IJN Naval Aviation Bureau in 1933. Then, following his tenure as Commander 2nd Fleet (1936), he was named the Commander of the Kure Naval District (1937-1938). Kato would later serve on the Supreme War Council (1939-1941) as Vice Navy Chief of Staff.
Third Fleet (1936)
Commander: Vice-Admiral Oikawa Koshiro
Composed of: 10th Squadron (including the armored cruisers Izumo, Kuma, 11th Squadron (including the river gunboats Ataka0, 5th Destroyer Squadron, 3rd Air Fleet (including the seaplane tenders Kamoi, Asanagi, Yūnagi).
Oikawa strongly supported the London Naval Treaty (1930) while a member of the Imperial Japanese Navy General Staff, and was thus a member of the “Treaty Faction” within the Navy. Following his tenure as Commander 3rd Fleet, Oikawa would be named Commander of the IJN Naval Aviation Bureau (1937-1938), where he would be succeeded by Yamamoto Isoroku. Promoted to Admiral in 1939, Oikawa was appointed as Minister of the Navy in the second and third cabinets of Prime Minister Fumimaro Konoe between 5 September 1940 and 18 October 1941. While Navy Minister, he strove to maintain ties with the United States, and instructed his naval attachés in Washington DC to work together with the Japanese ambassador to prevent war from breaking out. Likewise, he strongly opposed suggestions that Japan should declare war on the Soviet Union in early 1941. Oikawa served as Chief of the Navy General Staff in late 1944. He resigned in protest in May 1945 over Emperor Hirohito’s refusal to consider peace proposals at a time when the war was clearly already lost.
Training Fleet (1936)
Composed of: Iwate (cruiser, obsolete), Yakumo (armored cruiser, obsolete)
Launched in 1900 by Bristol Armstrong in the United Kingdom, Iwate participated in most of the naval battles of the Russo-Japanese War of 1904–05. The ship was moderately damaged during the Battle of Port Arthur, the Battle off Ulsan, and the Battle of Tsushima. Iwate played a minor role in World War I and began the first of her many training cruises for naval cadets in 1916, a task that would last until the end of 1939. The ship continued to conduct training in home waters throughout the Pacific War before being sunk at Kure in 1945.
Like Iwate, the armored cruiser Yakumo was also built and launched overseas – in Germany, in 1899. She participated in most of the naval battles of the Russo-Japanese War of 1904–05, and was lightly damaged during the Battle of the Yellow Sea and the Battle of Tsushima. Yakumo saw no combat during World War I and began the first of many training cruises in 1917, although she was not officially reclassified as a training ship until 1931. Her last training cruise was in 1939, but the ship continued to conduct training in home waters throughout the Pacific War. Yakumo became a repatriation transport after the war before being broken up in 1946–47.